Row Border in DataGrid 表格边框

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Row Border in DataGrid - jQuery EasyUI Demo</title>
    <link rel="stylesheet" type="text/css" href="../../themes/default/easyui.css">
    <link rel="stylesheet" type="text/css" href="../../themes/icon.css">
    <link rel="stylesheet" type="text/css" href="../demo.css">
    <script type="text/javascript" src="../../jquery-1.8.0.min.js"></script>
    <script type="text/javascript" src="../../jquery.easyui.min.js"></script>
</head>
<body>
    <h2>Row Border in DataGrid</h2>
    <div class="demo-info">
        <div class="demo-tip icon-tip"></div>
        <div>This sample shows how to change the row border style of datagrid.</div>
    </div>
    <div style="margin:10px 0;">
        <span>Border:</span>
        <select onchange="changeBorder(this.value)">
            <option value="lines-both">Both</option>
            <option value="lines-no">No Border</option>
            <option value="lines-right">Right Border</option>
            <option value="lines-bottom">Bottom Border</option>
        </select>
        <span>Striped:</span>
        <input type="checkbox" onclick="$('#dg').datagrid({striped:$(this).is(':checked')})">
    </div>
    <table id="dg" class="easyui-datagrid" title="Row Border in DataGrid" style="width:700px;height:250px"
            data-options="singleSelect:true,fitColumns:true,url:'../datagrid/datagrid_data1.json'">
        <thead>
            <tr>
                <th data-options="field:'itemid',width:80">Item ID</th>
                <th data-options="field:'productid',width:100">Product</th>
                <th data-options="field:'listprice',width:80,align:'right'">List Price</th>
                <th data-options="field:'unitcost',width:80,align:'right'">Unit Cost</th>
                <th data-options="field:'attr1',width:250">Attribute</th>
                <th data-options="field:'status',width:60,align:'center'">Status</th>
            </tr>
        </thead>
    </table>
    <script type="text/javascript">
        function changeBorder(cls){
            $('#dg').datagrid('getPanel').removeClass('lines-both lines-no lines-right lines-bottom').addClass(cls);
        }
    </script>
    <style type="text/css">
        .lines-both .datagrid-body td{
        }
        .lines-no .datagrid-body td{
            border-right:1px dotted transparent;
            border-bottom:1px dotted transparent;
        }
        .lines-right .datagrid-body td{
            border-bottom:1px dotted transparent;
        }
        .lines-bottom .datagrid-body td{
            border-right:1px dotted transparent;
        }
    </style>

</body>
</html>

 striped　　　　在默认css下没有效果，可能是css设置问题